A giant centipede monster appeared as a girl in armor with a sword and a giant boomerang came face to face with it! 

Sango (A Demon Slayer who comes from a village of demon slayers! Her main weapon is a massive boomerang that she carries around with her!) 

Sango: HIRAIKOTSU! 

She thew the massive boomerang and it cut the demon in two! 

There she found- 

Sango: A shard of the Shikon Jewel huh? 

Villagers: Thank you so much! 

Sango: If anything like this happens again, call me! 

She changed her clothes afterwards. 

Male Villager: Wait, are you really going to take that shard? 

Sango: Yes, you see the Shikon Jewel was originally from my village. 

Later... 

Team (Y/N) was in the same vicinity as you talked about what happened that night. 

Inuyasha: Kikyo was there?! 

(Y/N): Yeah, and I had to fight her, because she was hell bent on killing you. 

Inuyasha: I swear if she- 

(Y/N): Calm down, Inuyasha. She's fine. She won't be trying to kill you since I told her about Naraku. 

Weiss: The more I hear about Naraku, the more I really want to see him dead now. 

(Y/N): Yeah, the feeling is- WHOA! 

You saw the corpse of the giant centipede. 

Shippo: Wh-What happened here? 

Villager: Oh, this was the work of the Demon Slayer girl. 

(Y/N): Demon Slayer? 

Ruby: There are demon slayers in these parts? 

Villager: Yes, it was a beautiful girl, and we saw her kill the monster and take a shard of the Shikon Jewel from it for- 

Inuyasha: WHAT?! WHEN WAS THIS?! 

He grabbed the guy in anger. 

Kagome: UGH! SIT BOY! 

Inuyasha: AAAAAAAAAAAAAAARGH! 

Miroku: Do not worry yourself about him. He is my pupil in Buddhism. 

Inuyasha: WHO'S THE SERVANT?! 

Miroku: Back off, you'll only complicate things if you keep on talking. 

Inuyasha: Says the guy who will flirt with any woman who comes his wa- 

You hit both of them on the head. 

(Y/N): Let me do the talking, idiots. So, there's an entire village of them or not? 

Villager: Yes, we only see then when they turn up looking for demons. 

Yang: And what else did she say? 

Villager: She said something about the Shikon Jewel coming from her village. 

Everyone: WHAT?! 

(Y/N): Not even you knew Inuyasha? 

Inuyasha: No, when I heard about it, it was already in Kikyo's possession. 

(Y/N): She may be of help to us. We have to find this girl. 

At the Demon Slayer Village.... 

Sango: I'm back! 

Villagers: Welcome back Sango! What was it this time? 

Sango: A giant centipede. I even brought back some legs and a bit of the shell to use as armor. 

She then noticed a small nekomata coming for her! 

Kirara (Sango's pet Nekomata! Has the ability to transform and be used as transportation!) 

Sango: Hi Kirara! 

Sango hugged her beloved pet. 

Sango: Who's been a good girl? 

???: Sango! Welcome back! 

Kohaku (Sango's Little Brother! He's nervous about starting his career as a Demon Slayer!) 

Sango: Hello Kohaku! 

Kohaku: Father is asking for you. 

Sango: He is. Very well then. 

Sango went to talk to her father, the head of the village. 

Sango's Father: Well done Sango. 

Sango: Father, will this suppress the fragment's evil? 

The man had the shard placed near a shrine while he was praying. 

Sango's Father: Probably not. It is said that fifty years ago, it was entrusted to a powerful priestess who was able to purify it, but in the end that woman died in a battle over the jewel. All we can do now until we can find someone with purifying spiritual powers is collect the fragments and protect them in our village. Right now, you should get some rest. You have another job to do. As well as you Kohaku. It's about time you got out into battle at your age. 

Kohaku: R-Really? 

Later... 

Kohaku was slicing through some wooden stakes with a chain scythe. 

Kohaku: ... Still ... not good enough. 

Sango: Kohaku, are you scared? 

Kohaku: WH-WHAT?! Scared? I- uh ... 

Sango: You'll be fine. As we'll ever fight is giant snakes and spiders of course. Father told me that the scariest dmeons are the ones that can pass for humans. And if one of them got their hands on the Shikon Jewel, it would be terrible. 

Soon... 

Sango and Kohaku were informed about a demonic spider that attacks a castle every night. 

Sango's Father: These two are my son and daughter. They can handle anything. 

Sango: Do your best Kohaku. 

Deep in the castle... 

Retainer: My Lord, the giant spider has appeared again. Tonight may be the last of it. After this, I hope yu can recover. 

The lord looked a lot like Naraku. 

Lord: I see. I've been waiting for this day. 

Soon... 

The Demon Slayers continued their battle with the demon spider and after a long and arduous battle, the monster was down! 

Kohaku: Alright, I'll- 

But then something overtook Kohaku! 

Kohaku: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAARGH! 

Sango: K-Kohaku?! 

He angrily killed his father and the Demon Slayers around them. 

Sango: KOHAKU! WHAT ARE YOU DOING?! 

He then attacked her! 

Sango: KOHAKU! IT'S ME! 

She pinned him down and soon noticed a spider thread coming from him. 

Sango: That thread! 

She went to attack a retainer nearby, though the man was decapitated by the lord. 

Lord: That man was not him. I was thinking that Father's appearance was odd as of late. It seems he was possessed by a demon all along. What a tragic thing to befall the Demon Slayers. 

At the same time... 

You all found the village of the Demon Slayers. 

(Y/N): This is it. 

Blake: They kept it well hidden alright. 

Inuyasha: Something's not right though. I smell demon blood. 

(Y/N): Me too. 

You all go in to see the entire place filled with corpses. 

Ruby: OH MY GOD! 

Miroku: They fought with the demons, but- 

Inuyasha: They died. There's no mistaking it, this is the place. 

Suddenly you all noticed a being nearby! 

Kagome: AGH! Is that- 

(Y/N): A Nekomata?! Be careful, it could pounce! 

???: HEY! It's alright, they're not our enemies. 

Kirara turned back to her small self. 

???: Well, long time no see! 

Inuyasha: Wait, isn't that- 

(Y/N): MYOUGA?! 

The small flea had been hiding inside of Kirara's fur. 

Inuyasha: What are you doing here? 

Miroku: Is he an acquaintance? 

Blake: He serves Inuyasha's family. 

Myouga: This is the Hidden Village of the Demon Slayers alright. People of this place have been here for generation after generation and they made a living off of their services. 

(Y/N): Where did all of these demons come from? 

Myouga: Out of Saru Castle, the village was vulnerable when it was attacked. Personally, I have a bad feeling about all of this. 

Back with Sango... 

Sango was in recovery as Kohaku had sustained heavy injuries and was put down due to his actions. 

Lord: You're Sango right? I am sorry about your father, brother, and companions. 

???: Young Master. 

Naraku appeared. 

Naraku: The village was attacked by a half-demon by the name of Inuyasha. 

Lord: Is that so? 

Naraku: Since the jewel was shattered he goes after those who possess the Shikon Jewel. With it he wishes to become a true demon. 

Lord: That girl, Sango, her village had a piece of the Shikon Jewel? 

Naraku: As it's a village of demon slayers, it is likely that he did that to the village to get his hands on it. 

Lord: Poor Sango, she has no home to go back to. 

Sango then came in. 

Lord: Sango. 

Sango: GIVE ME MY HIRAIKOTSU! I'LL FIND THE BASTARD WHO DID THAT TO MY VILLAGE AND KILL HIM! 

Soon... 

Naraku was guiding Sango as she was still in pain. 

Naraku: Sango, at this rate you'll die on the way. Here. 

He gave her a fragment of the Shikon Jewel. 

Sango: Why do you have that!? Where did you- 

Naraku: I obtained it quite a while ago. I'm going to lend it to you. There are people who can use this for good.